I saw a demonstration of an RF detector being brought close to a mobile phone. As the detector was moved away, the number on it dropped to zero. How can that be? Shouldn’t there be some RF signal from the phone all the way to the cell tower, so that the phone can communicate with the tower?

Question

I saw a demonstration of an RF detector being brought close to a mobile phone. As the detector was moved away, the number on it dropped to zero. How can that be? Shouldn’t there be some RF signal from the phone all the way to the cell tower, so that the phone can communicate with the tower?

In: Technology

Answer 1

Your RF “detector” is essentially a piece of shit.

Go on amazon, get a software defined radio dongle. They are less than $100, download some apps that has a spectrum analyzer. You’ll be able to see the different bands your cellphone uses, although you probably won’t see Bluetooth/wifi cause the ones I saw only go to 1.7GHz.

Your cellphone has a chip for the different GSM bands, probably a built in NFC reader, Bluetooth, wifi and the ability to receive GPS/GLONASS and if it’s newer the new EU Galileo positioning system.

A spectrum analyzer is a better tool for identifying RF radiation. Pair it with a high gain directional antenna and you could even locate the source of RF transmitters from far away.